Integrated Circuitry Comprising Nonvolatile memory Cells And Methods Of Forming A Nonvolatile Memory Cell

ABSTRACT

An integrated circuit has a nonvolatile memory cell that includes a first electrode, a second electrode, and an ion conductive material there-between. At least one of the first and second electrodes has an electrochemically active surface received directly against the ion conductive material. The second electrode is elevationally outward of the first electrode. The first electrode extends laterally in a first direction and the ion conductive material extends in a second direction different from and intersecting the first direction. The first electrode is received directly against the ion conductive material only where the first and second directions intersect. Other embodiments, including method embodiments, are disclosed.

TECHNICAL FIELD

Embodiments disclosed herein pertain to memory cells of integratedcircuitry, and to methods of forming memory cells.

BACKGROUND

Memory is one type of integrated circuitry, and is used in computersystems for storing data. Such is usually fabricated in one or morearrays of individual memory cells. The memory cells might be volatile,semivolatile, or nonvolatile. Nonvolatile memory cells can store datafor extended periods of time, in many instances including when thecomputer is turned off. Volatile memory dissipates and thereforerequires to be refreshed/rewritten, in many instances multiple times persecond. Regardless, the smallest unit in each array is termed as amemory cell and is configured to retain or store memory in at least twodifferent selectable states. In a binary system, the states areconsidered as either a “0” or a “1”. In other systems, at least someindividual memory cells may be configured to store more than two levelsor states of information.

Integrated circuitry fabrication continues to strive to produce smallerand denser integrated circuits. Accordingly, the fewer components anindividual circuit device has, the smaller the construction of thefinished device can be. Likely the smallest and simplest memory cellwill be comprised of two current conductive electrodes having aprogrammable material received there-between. The programmable materialis selected or designed to be configured in a selected one of at leasttwo different resistive states to enable storing of information by anindividual memory cell. The reading of the cell comprises determinationof which of the states the programmable material is in, and the writingof information to the cell comprises placing the programmable materialin a predetermined resistive state. Some programmable materials retain aresistive state in the absence of refresh, and thus may be incorporatedinto nonvolatile memory cells.

One example memory device is a programmable metallization cell (PMC).Such may be alternatively referred to as conductive bridging RAM(CBRAM), nanobridge memory, or electrolyte memory. A PMC uses ionconductive material (for instance, a suitable chalcogenide or any ofvarious suitable oxides) sandwiched between a pair of electrodes. Asuitable voltage applied across the electrodes generates currentconductive super-ionic clusters or filaments. Such result from iontransport through the ion conductive material which grows theclusters/filaments from one of the electrodes (the cathode), through theion conductive material, and toward the other electrode (the anode). Theclusters or filaments create current conductive paths between theelectrodes. An opposite voltage applied across electrodes essentiallyreverses the process and thus removes the current conductive paths. APMC thus comprises a high resistance state (corresponding to the statelacking a current conductive filament or clusters between theelectrodes) and a low resistance state (corresponding to the statehaving a current conductive filament or clusters between theelectrodes), with such states being reversibly interchangeable with oneanother.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a hybrid schematic and fragmentary structural view of aportion of an integrated circuit in accordance with an embodiment of theinvention.

FIG. 2 is a sectional view of a portion of FIG. 1 taken through line 2-2in FIG. 1.

FIG. 3 is a sectional view of a portion of FIG. 1 taken through line 3-3in FIG. 1.

FIG. 4 is a sectional view of a portion of FIG. 1 taken through line 4-4in FIG. 1.

FIG. 5 is a hybrid schematic and fragmentary structural view of aportion of an alternate embodiment integrated circuit in accordance withan aspect of the invention.

FIG. 6 is a diagrammatic sectional view of a substrate fragment inprocess in accordance with an embodiment of the invention.

FIG. 7 is a view of the FIG. 6 substrate at a processing step subsequentto that shown by FIG. 6.

FIG. 8 is a view of the FIG. 7 substrate, at 90° to the FIG. 7 crosssection, at a processing step subsequent to that shown by FIG. 7.

FIG. 9 is a diagrammatic top-down view of the FIG. 8 substrate.

FIG. 10 is a view of the FIG. 8 substrate at a processing stepsubsequent to that shown by FIG. 8.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

Embodiments of the invention encompass integrated circuitry comprising anonvolatile memory cell, and methods of forming a nonvolatile memorycell. Referring initially to FIGS. 1-4, an example integrated circuit 10comprises a plurality of nonvolatile memory cells 14 formed within amemory array 12. An individual memory cell 14 comprises a first currentconductive electrode 16, a second current conductive electrode 18 formedelevationally outward thereof, and an ion conductive material 20received between such electrodes. A material 22, which may be homogenousor non-homogenous, may surround components 16, 18 and 20. Material 22 isnot shown in FIG. 1 for clarity in depicting the operable components.Material 22 would likely be insulative at least where contactingcomponents 16, 18, and 20 in the figures, with doped silicon dioxidebeing an example.

Components 16, 18, 20 and material 22 may be fabricated relative to orsupported by a suitable base substrate (not shown), for example asemiconductor substrate which may comprise monocrystalline siliconand/or other semiconductive material. The term “semiconductor substrate”means any construction comprising semiconductive material, including,but not limited to, bulk semiconductive materials such as asemiconductive wafer (either alone or in assemblies comprising othermaterials), and semiconductive material layers (either alone or inassemblies comprising other materials). The term “substrate” refers toany supporting structure, including, but not limited to, thesemiconductor substrates described above.

Electrodes 16 and 18 may comprise any suitable current conductivematerial, and may be homogenous or non-homogenous. In the context ofthis document, “current conductive material” is a composition whereelectric current flow would inherently occur therein predominantly bymovement of subatomic positive and/or negative charges when such aregenerated as opposed to predominantly by movement of ions. At least oneof first electrode 16 and second electrode 18 has an electrochemicallyactive surface received directly against ion conductive material 20. Inthis document, a material or structure is “directly against” anotherwhen there is at least some physical touching contact of the statedmaterials or structures relative one another. In contrast, “over”encompasses “directly against” as well as constructions whereintervening material(s) or structure(s) result in no physical touchingcontact of the stated materials or structures relative one another. Byway of examples only, suitable current conductive and electrochemicallyactive materials include copper, silver, and alloys including at leastone of copper and silver. Example suitable current conductive andelectrochemically inactive materials include titanium nitride, gold,tungsten, platinum, and alloys including at least one of gold, tungstenor platinum.

Ion conductive material 20 may be a solid, gel, or any other suitablephase, and may be homogenous or non-homogenous. Example suitablematerials comprise chalcogenide-type (for instance, materials comprisingone or more of germanium, selenium, antimony, tellurium, sulfur, copper,etc.; with example chalcogenide-type materials being Ge₂Sb₂Te₅, GeS₂,GeSe₂, CuS₂, and CuTe) and/or oxides such as zirconium oxide, hafniumoxide, tungsten oxide, silicon oxide (specifically, silicon dioxide),gadolinium oxide, etc. Such may have silver ions or other suitable ionsdiffused therein for ionic conduction, analogously to structuresdisclosed in U.S. Pat. No. 7,405,967 and U.S. Patent Publication Number2010/0193758.

In one embodiment, second electrode 18 may be considered as having alateral outermost sidewall 21 (FIGS. 2 and 3) and ion conductivematerial 20 may be considered as having a transverse outermost sidewall24 (FIG. 2) received directly against such second electrode sidewall 21.In one embodiment, such may be vertically oriented at least where eachis directly received against the other. In this document, vertical is adirection generally orthogonal to a primary surface relative to whichthe substrate is processed during fabrication and which may beconsidered to define a generally horizontal direction. Further,“vertical” and “horizontal” as used herein are general perpendiculardirections relative one another independent of orientation of thesubstrate in three dimensional space. Further in this document,“elevationally outward” is with reference to the vertical direction froma base substrate upon which the circuitry is fabricated.

In one embodiment, first electrode 16 may extend laterally in a firstdirection 26 and ion conductive material 20 may extend laterally in asecond direction 28 different from and intersecting first direction 26.Accordingly, such angle relative to one another, with reference to“angle” herein meaning any angle other than the straight angle. In oneembodiment, first and second directions 26, 28 intersect at an anglefrom about 45° to 90°, and in one embodiment from 80° to 90°. Such areshown in FIGS. 1-4 as intersecting at a 90° angle 29 (FIG. 4), as anexample. First direction 26 and direction 28 may be parallel to thehorizontal direction.

Regardless and referring to FIG. 4, in one embodiment ion conductivematerial 20 and first electrode 16 may be considered as contacting oneanother at a maximum contacting area 30. Such is defined by a transversethickness 32 of ion conductive material 20 and a transverse thickness 34of first electrode 16 where such cross at angle 29 of intersectingdirections 26 and 28. Such may provide an advantage of more preciselydefining a position from where a conduction channel through material 20will initiate upon programming to a low resistance state. Such may alsoprovide an advantage of assuring formation of only a single conductionchannel, where such is desired. In one embodiment, at least one of firstelectrode 16 and ion conductive material 20 has its respectivetransverse thickness where such cross which is less than F, where F is aminimum feature dimension of lithographically-defined features of thesubstrate (meaning the minimum of all feature dimensions which aredefined lithographically). Regardless, an example thickness range 32 forion conductive material 20 is from about 2 to 30 nanometers, while thatfor first electrode 16 is from about 2 to 20 nanometers (thickness 34).In one embodiment, each of the first electrode 16 and ion conductivematerial 20 has a respective uniform transverse thickness which may bethe same or different from each other, with different thicknesses beingshown.

First electrode 16 may be considered as having an elevationally outersurface 36 with, in one embodiment, at least a portion thereof beingreceived directly against ion conductive material 20. Analogously,second electrode sidewall 21 may be considered as comprising a surfacereceived directly against ion conductive material 20. At least a portionof at least one of sidewall 21 or surface 36 as received directlyagainst ion conductive material 20 is electrochemically active.Accordingly, second electrode 18 and/or first electrode 16 has someelectrochemically active surface received directly against ionconductive material 20.

In one embodiment, at least second electrode 18 comprises anelectrochemically active surface. By way of example, second electrode 18is shown as comprising a composite of current conductive material 40 andcurrent conductive material 42, with material 42 in one embodiment alsoconstituting an electrochemically active material having a surface 21which is received directly against ion conductive material 20. Material40 and material 42 may, respectively, be homogenous or non-homogenous.An example thickness range for current conductive and electrochemicallyactive material 42 is from about 2 to 30 nanometers, while that forcurrent conductive material 40 is from about 10 to 80 nanometers.Current conductive material 40 may or may not also be electrochemicallyactive, and in one embodiment is electrochemically inactive, for examplecomprising elemental tungsten. In one embodiment, the current conductivematerial of first electrode 16 may be electrochemically inactive, againwith elemental tungsten being one specific example.

Within array 12, material 42 and/or material 40 may extend/runcontinuously in individual of the column/row lines, or first electrode16 may run continuously in individual of the column/row lines.Regardless, ion conductive material 20 may extend/run continuously in aline, may be continuous throughout the array, or may be patterned withdefined edges for individual of the memory cells. As an example only,FIGS. 1-4 show material 40 and ion conductive material 20 extendingalong or as respective continuous lines, with material 42 and firstelectrode 16 being isolated structures for each memory cell 14.

In one embodiment where at least the second electrode comprises anelectrochemically active material having a surface directly against ionconductive material, the ion conductive material has an elevationallyoutermost surface which is elevationally outward of an elevationallyoutermost surface of the electrochemically active material. For examplein the embodiment of FIGS. 1-4, electrochemically active material 42 maybe considered as having an elevationally outermost surface 46 and ionconductive material 20 may be considered as having an elevationallyoutermost surface 48. Surface 48 is elevationally outward of surface 46.In one embodiment, the second electrode may comprise anelectrochemically inactive material which is received elevationallyoutward of the electrochemically active material of the secondelectrode. The electrochemically inactive material comprises anelevationally outermost surface which is elevationally coincident withthe elevationally outermost surface of the ion conductive material. Forexample in the embodiment of FIGS. 1-4 where material 42 iselectrochemically active and material 40 is electrochemically inactive,material 40 comprises an elevationally outermost surface 50 which iselevationally coincident with surface 48 of ion conductive material 20.

In one embodiment, each of the first electrode, the second electrode,and the ion conductive material is platelike and orientedperpendicularly relative each other. In the context of this document,“platelike” defines a construction having length and width dimensionswhich are each at least 2.5 times greater than a maximum transversethickness/depth of the construction orthogonal to the length and width.FIG. 1 depicts such a construction where each of electrodes 16, 18 andion conductive material 20 is platelike (having edge surfaces) andperpendicularly oriented relative to each other. Any other attribute mayapply as described above. By way of example, the second platelikeelectrode may comprise an electrochemically active surface receiveddirectly against the platelike ion conductive material. Further as anexample, the platelike ion conductive material may comprise anelevationally outermost surface having the second electrode receiveddirectly there-against, for example as shown in the embodiment of FIG.5. The electrodes and ion conductive material of the embodiments ofFIGS. 1 and 5 may be considered respectively as being platelike in avolume expanse encompassing an individual memory cell 14/14 a even ifone or more of such extends or runs continuously in an individual lineor is otherwise continuous in some aspect other than shown.

FIGS. 2 and 3 diagrammatically depict memory cell 14 as being programmedin an example low resistance “1” state wherein a low electricalresistance/current conduction path 44 has been formed through ionconductive material 20. Conduction path 44 extends from and betweensurface 36 of first electrode 16 and sidewall 21 of current conductivematerial 42 where such are each received directly against ion conductivematerial 20. Conduction path 44 may be in the form of a path of currentconductive particles which may or may not be directly against oneanother, with single ions and super-ionic clusters being examples. Insome embodiments, the conduction path may be a filament, for example asdescribed in U.S. Patent Publication No. 2010/01100759. Conduction path44 may be formed by application of a suitable electric field through ionconductive material 20 to cause ions from the electrochemically activesurface of one electrode to pass towards the opposing electrode and growconduction path 44 through ion conductive material 20 from such opposingelectrode. Such may be achieved by providing a suitable voltagedifferential to electrodes 16 and 18. Memory cell 14 may be programmedto an example high resistance “0” state by at least reversing polarityof the voltage differential to reverse the process, thereby removingconduction path 44. Memory cell 14 may thereby be repeatedlyprogrammable between at least two programmed states by application ofsuitable voltage differentials to move between programmed states.

FIG. 1 depicts but one example architecture for array 12 of integratedcircuit 10. In such, memory cell 14 is connected between or as portionsof a schematically illustrated field effect transistor 100 and aschematically illustrated data/sense line 102 (i.e., a bit line). Firstelectrode 16 is connected with or comprises one source/drain region oftransistor 100, with the other source/drain region thereof connected toa suitable potential depicted as ground in FIG. 1, as an example. Thegate of field effect transistor 100 may comprise a control line 104(i.e., a word line) of a row line or column line of memory cells 14. Bitline 102 may comprise a corresponding other of a row line or column lineof memory cells 14.

Some or all of second electrodes 18 in an individual data/sense line 102may extend continuously along such data/sense line. As an examplealternate embodiment, the architecture may be reversed. For example,some or all of first electrodes 16 may extend continuously along anindividual control line, and individual second electrodes 18 may beisolated constructions relative one another along a correspondingdata/sense line. Further and regardless, the roles of data/sense andcontrol lines may be reversed.

An alternate embodiment nonvolatile memory cell 14 a is shown in FIG. 5in comparison to a single memory cell 14 in FIG. 1. Like numerals fromthe above-described memory cell 14 are used where appropriate, with someconstruction differences being indicated with the suffix “a”. In memorycell 14 a, second electrode 18 a is received directly againstelevationally outermost surface 48 of ion conductive material 20. Anyother attribute as described above may apply to the nonvolatile memorycell construction 14 a of FIG. 5. As an alternate example, in oneembodiment, second electrode 18/18 a might be oriented edgewise (notshown) such that it is oriented like first electrode 16, for example anyof directly over and parallel thereto, not directly over and parallelthereto, and directly over or not directly over yet angled relative tofirst electrode 16.

Embodiments of the invention encompass methods of forming a nonvolatilememory cell. Example such methods are described with reference to FIGS.6-10 with respect to a substrate fragment 60 in fabrication of anonvolatile memory cell of the FIGS. 1-4 embodiments. The artisan willappreciate that the FIG. 5 or other nonvolatile memory cells may also oralternately be fabricated. Further and regardless, the fabricationmethods disclosed herein are not necessarily limited by the structuralaspects described above, nor are any structural aspects described abovenecessarily limited by methods of fabrication, unless so claimed.

Referring to FIG. 6, substrate 60 may comprise a semiconductorsubstrate, and is shown as comprising a material 62 having a firstsidewall 64. Material 62 may be of any composition, may be homogenous ornon-homogenous, and sidewall 64 may be vertically oriented. An examplematerial 62 is some portion of material 22 of the above-describedembodiments.

Referring to FIG. 7, a first current conductive electrode material 66has been formed over first sidewall 64. In one embodiment, material 66is formed to have a transverse thickness (thickness orthogonal tosidewall 64) which is less than F. An example technique for formingmaterial 66 is by any suitable conformal deposition of material 66 overmaterial 62, followed by anisotropic etching thereof to clear material66 from the outer surfaces of material 62. Such may be conducted with orwithout masking. Regardless, alternate or additional techniques may beused. First current conductive electrode material 66 may have any of theattributes, including but not limited to “shape”, of first electrode 16described above. Accordingly, first current conductive electrodematerial 66 may be first electrode 16 of the FIGS. 1-4 embodiment.

Referring to FIGS. 8 and 9, a second sidewall 68 has been formedelevationally outward of first current conductive material material 66,and first and second sidewalls 64, 68 have been formed at an angle 65relative one another. In one embodiment, such angle is from about 45° to90°, in one embodiment from 80° to 90°, and with an angle of 90° beingshown. Sidewall 64 may be vertically oriented. In the embodiment ofFIGS. 8 and 9, a material 63 has been formed over material 62 and firstcurrent conductive electrode material 66 and second current conductiveelectrode 18 have been provided relative thereto. Material 63 may be ofthe same composition as material 62. Materials 62 and 63 might beconsidered as a composite of material 22 of the embodiments of FIGS.1-4.

Referring to FIG. 10, an ion conductive material 70 has been formed oversecond sidewall 68 and directly against an elevationally outer surface36 of first current conductive material 66. Example materials andattributes are as described above with respect to ion conductivematerial 20. Accordingly, ion conductive material 70 may be ionconductive material 20 in the first described embodiments. An exampletechnique for forming ion conductive material 70 is by any suitableconformal deposition of material 70 over materials 40, 63, and 62,followed by anisotropic etching thereof to clear material 70 from theouter surfaces of materials 40, 63, and 62. Ion conductive material 70and first current conductive material 66 contact one another at amaximum contacting area defined by a transverse thickness of the ionconductive material and a transverse thickness of the first currentconductive electrode where such cross at their angle of intersection,for example analogous to and as depicted and described above withrespect to FIG. 4.

Regardless, a second current conductive electrode is provided directlyagainst the ion conductive material, with at least one of the firstcurrent conductive electrode and the second current conductive electrodehaving an electrochemically active surface directly against the ionconductive material. The second electrode may have any of the attributesas described above. Further, the ion conductive material may be formedbefore or after forming the second current conductive electrode. TheFIGS. 6-10 embodiment is an example wherein the ion conductive materialis formed after forming the second current conductive electrode.Alternately by way of example, FIG. 5 depicts an embodiment moreconducive to forming the ion conductive material before forming thesecond current conductive electrode.

An embodiment of the invention includes a method of forming anonvolatile memory cell comprising forming first and second electrodeswhere at least one of such has an electrochemically active surface, andindependent of any other attribute described above (although such areexample attributes which may be used in this embodiment). For example,such formation of first and second electrodes in accordance with thisembodiment is independent of elevational or other orientation of theelectrodes relative to each other. Regardless, after forming the firstand second electrodes, an ion conductive material is deposited directlyagainst the electrochemically active surface. Heretofore, the prior artis not understood to anywhere deposit an ion conductive materialdirectly against an electrochemically active surface of a first and/orsecond electrode after both such electrodes have been formed.

In one embodiment, a dielectric may be provided between the first andsecond electrodes, and have a lateral sidewall. The ion conductivematerial may also be deposited directly against the dielectric lateralsidewall. For example with respect to FIG. 8 where material 63 comprisesa dielectric, a portion of sidewall 68 (i.e., that which is belowmaterial 42) is a dielectric lateral sidewall directly against which ionconductive material 70 is deposited, for example as shown in FIG. 10.Any other attribute may be used as described above.

In compliance with the statute, the subject matter disclosed herein hasbeen described in language more or less specific as to structural andmethodical features. It is to be understood, however, that the claimsare not limited to the specific features shown and described, since themeans herein disclosed comprise example embodiments. The claims are thusto be afforded full scope as literally worded, and to be appropriatelyinterpreted in accordance with the doctrine of equivalents.

1. An integrated circuit comprising a nonvolatile memory cell, thenonvolatile memory cell comprising: a first electrode, a secondelectrode, and an ion conductive material between the first and secondelectrodes; at least one of the first and second electrodes having anelectrochemically active surface directly against the ion conductivematerial; the second electrode being elevationally outward of the firstelectrode; and the first electrode extending laterally in a firstdirection, the ion conductive material extending laterally in a seconddirection different from and intersecting the first direction, the firstelectrode being directly against the ion conductive material only wherethe first and second directions intersect.
 2. The integrated circuit ofclaim 1 wherein the second electrode has an electrochemically activesurface directly against the ion conductive material.
 3. The integratedcircuit of claim 1 wherein the first electrode has an electrochemicallyactive surface directly against the ion conductive material.
 4. Theintegrated circuit of claim 1 wherein the second electrode has a lateraloutermost sidewall and the ion conductive material has a transverseoutermost sidewall directly against the second electrode lateraloutermost sidewall.
 5. The integrated circuit of claim 4 wherein thelateral outermost sidewall and the transverse outermost sidewall arevertically oriented.
 6. The integrated circuit of claim 1 wherein theion conductive material comprises an elevationally outermost surface,the second electrode being directly against the elevationally outermostsurface of the ion conductive material.
 7. The integrated circuit ofclaim 1 wherein at least one of the first electrode and the ionconductive material has a transverse thickness where received directlyagainst the other of the first electrode or ion conductive materialwhich is less than F, where F is a minimum feature dimension oflithographically-defined features.
 8. The integrated circuit of claim 1wherein each of the first electrode and the ion conductive material hasa transverse thickness where received directly against the other of thefirst electrode or ion conductive material which is less than F, where Fis a minimum feature dimension of lithographically-defined features. 9.The integrated circuit of claim 1 wherein the first and seconddirections intersect at an angle from about 45° to 90°.
 10. Theintegrated circuit of claim 9 wherein the first and second directionsintersect at an angle from 80° to 90°.
 11. The integrated circuit ofclaim 1 wherein each of the first electrode and the ion conductivematerial is platelike.
 12. The integrated circuit of claim 1 whereineach of the first electrode and the ion conductive material is platelikeand are intersecting at about 90°.
 13. The integrated circuit of claim 1comprising a plurality of said nonvolatile memory cells within a memoryarray.
 14. An integrated circuit comprising a nonvolatile memory cell,the nonvolatile memory cell comprising: a first platelike electrode, asecond platelike electrode, and a platelike ion conductive materialbetween the first and second platelike electrodes; at least one of thefirst and second platelike electrodes having an electrochemically activesurface directly against the platelike ion conductive material; thesecond platelike electrode being elevationally outward of the firstplatelike electrode; and each of the first platelike electrode, thesecond platelike electrode, and the platelike ion conductive materialbeing oriented perpendicularly relative each other.
 15. The integratedcircuit of claim 14 wherein the second platelike electrode comprises anelectrochemically active surface directly against the platelike ionconductive material.
 16. The integrated circuit of claim 14 wherein thesecond platelike electrode comprises an electrochemically activematerial having an electrochemically active surface directly against theplatelike ion conductive material, the electrochemically active materialof the second platelike electrode having an elevationally outermostsurface that is not received against the platelike ion conductivematerial.
 17. The integrated circuit of claim 16 wherein the ionconductive material has an elevationally outermost surface which iselevationally outward of the elevationally outermost surface of theelectrochemically active material of the second platelike electrode. 18.The integrated circuit of claim 14 wherein the platelike ion conductivematerial comprises an elevationally outermost surface, the platelikesecond electrode being directly against the elevationally outermostsurface of the platelike ion conductive material.
 19. The integratedcircuit of claim 14 wherein each of the first platelike electrode andplatelike ion conductive material is of a respective uniform transversethickness.
 20. The integrated circuit of claim 14 wherein each of thefirst platelike electrode and the platelike ion conductive material areof a respective uniform transverse thickness which is less than F, whereF is a minimum feature dimension of lithographically-defined features.21. An integrated circuit comprising a nonvolatile memory cell, thenonvolatile memory cell comprising: a first electrode, a secondelectrode, and an ion conductive material between the first and secondelectrodes; at least the second electrode comprising anelectrochemically active material having a surface directly against theion conductive material; the second electrode being elevationallyoutward of the first electrode; and the electrochemically activematerial having an elevationally outermost surface, the ion conductivematerial having an elevationally outermost surface which iselevationally outward of the elevationally outermost surface of theelectrochemically active material.
 22. The integrated circuit of claim21 wherein the second electrode comprises an electrochemically inactivematerial received elevationally outward of the second electrodeelectrochemically active material, the electrochemically inactivematerial comprising an elevationally outermost surface which iselevationally coincident with the elevationally outermost surface of theion conductive material.
 23. The integrated circuit of claim 21 whereinthe first electrode extends laterally in a first direction, the ionconductive material extends laterally in a second direction differentfrom and intersecting the first direction, the first electrode beingdirectly against the ion conductive material only where the first andsecond directions intersect.
 24. The integrated circuit of claim 21wherein each of the first electrode, the second electrode, and the ionconductive material is platelike.
 25. The integrated circuit of claim 24wherein each of the platelike first electrode, the platelike secondelectrode, and the platelike ion conductive material is orientedperpendicularly relative each other.
 26. The integrated circuit of claim21 wherein the second electrode has a lateral outermost sidewall and theion conductive material has a transverse outermost sidewall directlyagainst the second electrode lateral outermost sidewall.
 27. Anintegrated circuit comprising a nonvolatile memory cell, the nonvolatilememory cell comprising: a first electrode, a second electrode, and anion conductive material between the first and second electrodes; atleast one of the first and second electrodes having an electrochemicallyactive surface directly against the ion conductive material; the secondelectrode being elevationally outward of the first electrode and havinga lateral outermost sidewall; and the ion conductive material comprisinga transverse outermost sidewall directly against the second electrodelateral outermost sidewall.
 28. The integrated circuit of claim 27wherein each of the first electrode, the second electrode, and the ionconductive material is platelike.
 29. The integrated circuit of claim 28wherein each of the platelike first electrode, the platelike secondelectrode, and the platelike ion conductive material is orientedperpendicularly relative each other.
 30. The integrated circuit of claim27 wherein the lateral outermost sidewall and the transverse outermostsidewall are vertically oriented.
 31. A method of forming a nonvolatilememory cell, comprising: forming first and second electrodes, at leastone of the first and second electrodes having an electrochemicallyactive surface; and after forming the first and second electrodes,depositing an ion conductive material directly against theelectrochemically active surface. 32-36. (canceled)
 37. A method offorming a nonvolatile memory cell, comprising: forming a first sidewall;forming a first current conductive electrode material over the firstsidewall; forming a second sidewall elevationally outward of the firstcurrent conductive material, the first and second sidewalls being formedat an angle relative one another; forming an ion conductive materialover the second sidewall and directly against an elevationally outersurface of the first current conductive material, the ion conductivematerial and the first current conductive material contacting oneanother at a maximum contacting area defined by a transverse thicknessof the ion conductive material and a transverse thickness of the firstcurrent conductive electrode where such cross at said angle; andproviding a second current conductive electrode directly against the ionconductive material, at least one of the first current conductiveelectrode and the second current conductive electrode having anelectrochemically active surface directly against the ion conductivematerial. 38-48. (canceled)